The disclosure relates to a segmented breaker roll apparatus. More specifically, it relates to a segmented breaker roll apparatus for eliminating or minimizing coil breaks in metal strips.
Coiling of sheet metal has long been recognized to impart an arcuate curvature or bend to the metal also known as a series of very small bends or “coil breaks”. Most manufactured products require that the sheet metal be substantially flat, thus making it necessary to remove coil set during processing of the sheet metal. Coil set can be removed by removing or unwinding the sheet metal from a coil and feeding it through a roller leveler apparatus having multiple offset rolls.
However, as steel is uncoiled on a processing line, the strip is bent in the opposite direction of the natural coil radius at least one or more times. Consequently, as the strip is uncoiled, undesirable and unsightly non uniform bend marks (i.e., “coil breaks”) can be produced in the strip. As the coil radius decreases during pay off or unrolling, the severity of the break marks increase. By controlling the uncoiling process, the marks can be eliminated or controlled as to the severity and location.
Existing uncoiler machines use a full face mandrel. The full face mandrel style has a mandrel face width that is wide enough to support a maximum width coil. This type of uncoiler does not need a segmented breaker roll because a typical, full face breaker roll could be engaged and follow the coil outer diameter until the coil is completely uncoiled. In this instance there is no interference between the breaker roll and the uncoiler machine and thus no need for segmented breaker rolls.
However, with a double stub, or double cone uncoiler machine, there are two uncoiler heads that come in against the side walls of the coil and protrude partially into the inner diameter of the coil. The wider the coil, the farther apart the two uncoiler heads need to be spaced. With narrow coils the two uncoiler heads come very close to each other. The wide coils need a wide face breaker roll. However, if a wide face breaker roll were used and the uncoilers are close to each other for a narrow coil, the wide face breaker roll could not be lowered between the two uncoiler heads; rather, it would hit the heads as the coil diameter reduced and payed down. A segmented breaker roll configuration keeps this from happening by keeping the “outer” elements of its roll face above the uncoiler heads.
Another problem with existing devices is that the rolls used to reduce coil breaks can only accommodate a specific coil width. If the roll has a width less than that of the coil, the coil break will not be properly eliminated or minimized.
Another problem with existing devices is that as the diameter of the coil decreases, the roll does not adjust to accommodate the decreasing diameter of the coil.
Thus, it is desired to provide a segmented breaker roll apparatus which overcomes the above-mentioned deficiencies and others while providing better overall results. The apparatus applies a controlled force to the strip by means of various rolls which can be extended or retracted with respect to the coil as needed to accommodate various widths and diameters of the coil and to effectively eliminate or control coil breaks.